What's the Big Deal?

Seriously, what’s the big deal?:

The topic of gut health is a popular one these days, and it's not all that new. The observations associated with a gut-brain axis, where the gut has the potential to affect emotions, behavior, cognition, and even pain management are quite ancient. Fecal transplants have been used in Traditional Chinese Medicine since the Dong-Jin dynasties (years 265-420). This idea of fecal transplantation was researched in the 17th century. The use of milk products as a remedy for gastrointestinal complaints can be seen in the works of Hippocrates, Avicenna, Galen, Pliny the Elder, and the Bible. It wasn't until the 18th century that Vitalists looked at the gut-brain axis in a more systematic way. In the 19th century physicians blamed the gastrointestinal system for it's influence on the mind. 20th century researchers took a different view believing that the mind was responsible for issues experienced in the gut. And finally, 21st century experts have been able to apply modern research methods to help give this subject new life, thrusting it into the spotlight.

Research shows that the digestive system and the brain are intricately related, and this goes beyond the saliva that is produced when we smell food. Based on more recent research, the gut, in close connection with its resident microbes (the microbiome), has the ability to influence pain sensitivity, social interactions, basic emotions, and even lead many of the decisions people make.

The gut has its own nervous system made up of as many nerve cells as are contained in the spinal cord. The largest part of the body’s immune system lies within the gut. The lining of the gut also contains a huge number of endocrine cells, housing about 20 different kinds of hormones. And the gut is the largest warehouse in the body for serotonin, making up 95% of the body’s stores. Serotonin is the signaling molecule that plays the most important role in the gut-brain axis. It is important for the normal gut functions such as coordinating contractions that propel food through, and in addition, sleep, pain sensitivity, appetite, mood, and overall well-being.

What is the gut-brain axis?

The gut is connected to the brain via bi-directional signaling pathways which include nerve cables, hormones, and inflammatory signaling molecules. The gut can send signals to the brain and the brain can send them back.

What can affect the health of the gut?

The food people eat, as well as the additives and preservatives in that food, can have an effect on the health of the gut. In addition, stress has been shown to cause the wall of the gut to become leakier. It can also cause the gut to contract more and the colon to secrete more mucus and water. Over-exercise may also cause an imbalance in the gut microbiome.

And just as these things can negatively affect gut health, they can positively affect it. For example, research has shown that individuals who perform moderate exercise may experience a reduction in inflammation in the gut as well as intestinal permeability. By decreasing stress, the effect of stress hormones on the gut will be lessened. Lastly, eating a healthy balanced diet including plant-based foods, complex carbohydrates, plant-derived fats, fish, naturally fermented foods, polyphenols, and plant-products that offer anti-inflammatory benefits (curcumin, turmeric, and ginger, for example) can have profound positive affects on the gut. This way of eating would be consistent with Mediterranean, traditional Japanese, Korean, or Chinese diets which are low in processed foods, sugar, meat, animal-derived fats and dairy.

Bottom line:

The health of the gut is vitally important for the health and well-being of the whole body. In order to achieve your health goals, it may be a good idea to first take inventory of the health of your gut.

References

Clauss, M., Gerard, P., Mosca, A., & Leclerc, M. (2021). Interplay Between Exercise and Gut Microbiome in the Context of Human Health and Performance. Front. Nutr., 8(637010), 1-15. Retrieved from https://www.frontiersin.org/articles/10.3389/fnut.2021.637010/full

Lewandowska-Pietruszka, Z., Figlerowicz, M., & Mazur-Melewska, K. (2022). The History of the Intestinal Microbiota and the Gut-Brain Axis. Pathogens (Basel, Switzerland), 11(12), 1540. https://doi.org/10.3390/pathogens11121540

Mayer, E. (2016). The Mind-Gut Connection. New York: HarperCollins.